The present invention is with respect to a rechargeable low voltage power pack or cartridge having a housing, a rectifier, an accumulator and pins for use with a current outlet of a public electricity supply.
Such rechargeable low voltage power packs or cartridges have been used for some years as parts of flashlights, radios and the like.
Because such rechargeable low voltage power packs or cartridges are fixed in and made part of the apparatus to be powered thereby, no attempts have been made so far at designing such a rechargeable power cartridge as a separate unit, this being more specially because the design of the apparatus would then have to be changed specially for use with the unit. Furthermore, no attempt has been made as to designing a low voltage rechargeable power cartridge for use with an electricity supply other than the public supply, because such other supplies are only on hand to a limited degree and, when in the form for example of motorvehicle batteries, they quickly become run down.
Although electrical apparatus has been designed having a motorvehicle plug structure for connection with the vehicle's battery, such apparatus is then limited to the special voltage and current output from such a vehicle battery; it is only in the case of high-price and complex apparatus that there is any chance of switching over between 6 Volts and 12 Volts operation. In no such case, however, is the motorvehicle battery used for charging up a low voltage power pack with an accumulator for operation of apparatus using the power pack and, in fact, the motorvehicle battery itself is used for supplying the low voltage current so that operation of the apparatus is only possible when there is a connection with a motorvehicle battery.
Because, however, many forms of electrical apparatus are used in the home as well, as for example vacuum cleaners, lights, radios etc., it is then necessary for the separate forms of apparatus to be purchased twice over, and they may only be used with a public electricity outlet or with a motorvehicle battery. While it is true that such apparatus may be run on primary batteries, such batteries are quickly used up, so that operation therewith is high in price.
Because the electrical power as supplied for example by a motorvehicle battery is to be used as economically as possible because it is possible for the battery to be run down, such a power pack is only to be recharged from such a supply when the battery or the like is able to give the greatest amount of power or when no outlet of a public electricity supply is to hand.